VMS Help INITIALIZE, /QUEUE, Parameter  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 queue-name[:]

    Specifies the name of an execution queue or a generic queue. The
    queue name may be a string of 1 to 31 characters. The character
    string can include any uppercase and lowercase letters, digits,
    the dollar sign ($),  and the underscore (_), and must include at
    least one alphabetic character.